All altcoins can't be a scam. It's too much of an over-reaching statement to say that they're all a scam. That's like saying that all fast food joints have E.Coli or something.
Some altcoins are headed by respectful people, while others are even headed by governments.
Anything can be a scam, yes... but not all altcoins are scams.
Eth is definitely not a scam because of its integration into so many things.
I also take Wall Street moguls with a grain of salt. It might be beneficial to spread FUD then buy low and sell when price is up. Rinse and repeat.
Sure there are scams and useless coins and few will survive when it all comes crashing down. But those who will, I believe, will change the world as did biggest tech companies of today.
Blockchain is not going anywhere anytime soon.